OVERALL DESCRIPTION (provided by applicant) The Radiation Therapy Oncology Group (RTOG) is a multi-disciplinary cancer research group committed to improving the outcome of adults afflicted with malignancies for which new therapeutic approaches to loco-regional disease are needed. The Group is organized into disease site committees and working groups, scientific core committees, and administrative committees. The Group?s clinical research efforts continue to define new standards of care for patients with a diverse range of malignancies and to contribute to the understanding of the biology of these diseases. The Group consists of both clinical and laboratory investigators from more than 260 institutions across the United States and Canada and includes nearly 90 percent of all of the National NCI-designated comprehensive and clinical cancer centers. The Group?s objectives include: 1) to improve upon the survival of patients with those common forms of cancer for which loco-regional tumor control is an important determinant of outcomes; 2) to enhance such cancer patients? quality of life by optimizing structural and functional organ preservation while improving or maintaining survival results; and 3) to pursue new initiatives in drug development, technology assessment, outcomes methodology research, combined modality integration, and translational research to advance the first two objectives. The RTOG continues as the premiere cancer research organization focused on the systematic study of novel methods of delivering radiotherapy and the translational research questions underlying such an effort. In addition, its outstanding efforts in defining new standards for combined modality therapy for patients with advanced malignancies are uniquely facilitated by the Group?s scientific and administrative infrastructure.